Physical activity is a key component of energy balance and its promotion therefore an essential component in the prevention of child overweight. Few studies have examined multiple contextual influences on physical activity and sedentary behaviors of Latino-children 3-5 yr, who have the highest prevalence of at risk and overweight among low income US preschoolers. Research suggests interventions addressing childhood obesity that will be effective for among Latino families and their preschool children require cultural tailoring and a robust parent component. The proposed study will use qualitative methods to explore parental, family and home environment, and social-cultural influences on children's physical activity and sedentary behaviors;and identify barriers and facilitators to providing opportunities for physical activity from the perspectives of parents and WIC Program staff serving Latino populations in Rhode Island. Quantitative data on physical activity of parents and preschool children assessed by accelerometry and parental report will complement qualitative themes used to design an educational intervention to be administered by WIC. Four sequential phases include: Phase I: A: focus group discussions with parents of preschool-aged children enrolled in the WIC program in the state of Rhode Island, and B: In-depth interviews with WIC staff;Phase II: measurement of objective and reported physical activity of n=30 parents and their preschool-aged children;Phase III: development of an educational intervention that addresses: (a) parental, (b) family/home environment, and (c) socio-cultural influences on physical activity and sedentary behaviors of low income, Latino preschool children;Phase IV: qualitative evaluation and refinement of materials and protocols, resulting in a fully developed educational intervention suitable for formal testing through a subsequent RO1 application. The proposed research will add to current knowledge not only through a focus on low-income, Latino preschool children and their families, but also demonstrating the potential role organizations such as the WIC Program can play in building parenting capacity and skills through educational interventions to promote increased physical activity and decreased sedentary behaviors of this population at high risk of overweight. Public Health Relevance: The proposed research will explore parental, family and home environment, and social-cultural influences and identify barriers and facilitators to improving physical activity and sedentary behaviors of low-income, Latino, preschool children. Qualitative research findings from focus groups with parents and in-depth interviews with staff of the Special Supplemental Food Program for Women, Infants and Children (WIC) and quantitative data on physical activity of parents and children assess by accelerometry and parental report will be used to develop an educational intervention for this target population at high risk of overweight. Materials, scripts and protocols for individual, group and phone counseling to be delivered by WIC staff will be culturally tailored to promote early healthy physical activity behaviors in this organizational setting.